1 cup (two sticks) butter
2 cups creamy peanut butter
2 1/2 cups graham cracker crumbs
1 3/4 cup powdered sugar
2 cups chocolate chips
1/3 cup milk
Melt butter and peanut butter together in a sauce pan, stirring well. Remove from heat and add graham cracker crumbs and powdered sugar. Spread the mixture into the bottom of a pan (jelly roll pan for thin bars, 9x13 for thicker bars). Chill until firm. Melt the chocolate chips with the milk. Spread chocolate layer over crumb mixture. Chill until firm.
Cut into bars (24 or 48 depending on pan size). Wrap individually in plastic wrap or separate layers with waxed paper. Store in the freezer, if they last that long!
Frozen Peanut Butter Bars from 30 Day Gourmet.